Collapsible steering column assembly

Abstract

A collapsible steering column assembly having a variable energy absorption curve is disclosed. The assembly includes a column jacket and an energy absorption device defining a deformation channel. A strap, interconnecting the column jacket and the energy absorption device, is disposed within the channel and moves along a deformation path in response to collapse of the column jacket. A pin is moveable into the deformation channel by a pyrotechnic device to alter the deformation path. Accordingly, the energy absorption device absorbs energy at a first rate when the pin is not disposed in the deformation channel, and absorbs energy at a second higher rate when the pin is disposed in the deformation channel.

1. A collapsible steering column assembly for a vehicle, said assembly comprising:
 a column jacket moveable along a longitudinal axis in response to a collision event; 
 a release module releasably coupled to said column jacket for coupling said column jacket to the vehicle prior to the collision event and releasing said column jacket from the vehicle in response to movement of said column jacket along said longitudinal axis; 
 an energy absorption device coupled to one of said column jacket and said release module and defining a deformation channel and including a strap disposed within said deformation channel with said strap moveable through said deformation channel along a deformation path in response to movement of said column jacket along said longitudinal axis; 
 a pin moveable in an axial direction from an axial position where said pin is not in said deformation channel to another axial position where said pin is disposed in said deformation channel such that said pin contacts said strap to alter said deformation path of said strap through said deformation channel for increasing a resistance force resisting movement of said strap through said deformation channel to increase an amount of energy absorbed; and 
 an actuator for selectively moving said pin in the axial direction; 
 wherein said energy absorption device includes an anvil defining said deformation channel; and 
 wherein said anvil includes a first lobe and a second lobe and a depression disposed between said first lobe and said second lobe. 
 
     
     
       2. An assembly as set forth in  claim 1  wherein said actuator includes a pyrotechnic device. 
     
     
       3. An assembly as set forth in  claim 1  further comprising a plurality of actuator fasteners and wherein said actuator includes a plurality of wings with said plurality of actuator fasteners interconnecting said plurality of wings to said release module. 
     
     
       4. An assembly as set forth in  claim 1  wherein said strap is disposed against said first lobe, said depression and said second lobe prior to said longitudinal movement of said column jacket. 
     
     
       5. An assembly as set forth in  claim 1  wherein said energy absorption device is coupled to said release module and said actuator is fixedly connected to said energy absorption device. 
     
     
       6. An assembly as set forth in  claim 5  wherein said strap is fixedly attached to said column jacket. 
     
     
       7. An assembly as set forth in  claim 5  further comprising a connecting device for selectively coupling said strap to said column jacket. 
     
     
       8. An assembly as set forth in  claim 1  wherein said release module includes a first release module and a second release module and said energy absorption device includes a first energy absorption device coupled to one of said first release module and said column jacket and further includes a second energy absorption device coupled to one of said second release module and said column jacket. 
     
     
       9. An assembly as set forth in  claim 8  further including a connecting device for selectively interconnecting one of said first energy absorption device and said second energy absorption device to one of said column jacket and said release module. 
     
     
       10. An assembly as set forth in  claim 9  wherein said strap defines an aperture and said connecting device includes a shaft moveable into said aperture to couple said strap of one of said first energy absorption device and said second energy absorption device to one of said column jacket and said release module. 
     
     
       11. An assembly as set forth in  claim 9  wherein said first energy absorption device is coupled to said first release module and said strap of said first energy absorption device is fixedly attached to said column jacket. 
     
     
       12. An assembly as set forth in  claim 11  wherein said second energy absorption device is coupled to said second release module and said connecting device selectively connects said strap of said second energy absorption device to said bracket. 
     
     
       13. An assembly as set forth in  claim 1  further including a bracket attached to said column jacket and interconnecting said column jacket and said release module prior to the collision event. 
     
     
       14. A collapsible steering column assembly for a vehicle, said assembly comprising:
 a column jacket moveable along a longitudinal axis in response to a collision event; 
 a release module releasably coupled to said column jacket for coupling said column jacket to the vehicle prior to the collision event and releasing said column jacket from the vehicle in response to movement of said column jacket along said longitudinal axis; 
 an energy absorption device coupled to one of said column jacket and said release module and defining a deformation channel and including a strap disposed within said deformation channel with said strap moveable through said deformation channel along a deformation path in response to movement of said column jacket along said longitudinal axis; 
 a pin moveable into said deformation channel to alter said deformation path of said strap through said deformation channel for increasing a resistance force resisting movement of said strap through said deformation channel to increase an amount of energy absorbed; and 
 an actuator for selectively moving said pin into said deformation channel, wherein said energy absorption device is coupled to said release module and said actuator is fixedly connected to said energy absorption device, and said release module and said energy absorption device are integrally formed. 
 
     
     
       15. A collapsible steering column assembly for a vehicle, said assembly comprising:
 a column jacket moveable along a longitudinal axis in response to a collision event; 
 a release module releasably coupled to said column jacket for coupling said column jacket to the vehicle prior to the collision event and releasing said column jacket from the vehicle in response to movement of said column jacket along said longitudinal axis; 
 an energy absorption device coupled to one of said column jacket and said release module and defining a deformation channel and including a strap disposed within said deformation channel with said strap moveable through said deformation channel along a deformation path in response to movement of said column jacket along said longitudinal axis; 
 a pin moveable in an axial direction from an axial position where said pin is not in said deformation channel to another axial position where said pin is disposed in said deformation channel such that said pin contacts said strap to alter said deformation path of said stray through said deformation channel for increasing a resistance force resisting movement of said strap through said deformation channel to increase an amount of energy absorbed; and 
 an actuator for selectively moving said pin in the axial direction; 
 wherein said release module includes a first release module and a second release module and said energy absorption device includes a first energy absorption device coupled to one of said first release module and said column jacket and further includes a second energy absorption device coupled to one of said second release module and said column jacket; 
 further including a connecting device for selectively interconnecting one of said first energy absorption device and said second energy absorption device to one of said column jacket and said release module; 
 wherein said connecting device includes a pyrotechnic device for selectively moving said shaft into interlocking engagement with said aperture. 
 
     
     
       16. A collapsible steering column assembly for a vehicle, said assembly comprising:
 a column jacket moveable along a longitudinal axis in response to a collision event; 
 a release module releasably coupled to said column jacket for coupling said column jacket to the vehicle prior to the collision event and releasing said column jacket from the vehicle in response to movement of said column jacket along said longitudinal axis; 
 an energy absorption device directly coupled to said release module and defining a deformation channel and including a strap disposed within said deformation channel with said strap moveable through said deformation channel along a deformation path in response to movement of said column jacket along said longitudinal axis; and 
 an axially extending pin moveable in an axial direction from a first axial position axially displaced outside of said deformation channel to a second axial position where said pin is disposed in said deformation channel such that said pin contacts said strap to alter said deformation path of said strap through said deformation channel for increasing a resistance force resisting movement of said strap through said deformation channel to increase an amount of energy absorbed; 
 wherein said energy absorption device includes an anvil defining said deformation channel; and 
 wherein said anvil includes a first lobe and a second lobe and a depression disposed between said first lobe and said second lobe. 
 
     
     
       17. A collapsible steering column assembly for a vehicle, said assembly comprising:
 a column jacket moveable along a longitudinal axis in response to a collision event; 
 a release module releasably coupled to said column jacket for coupling said column jacket to the vehicle prior to the collision event and releasing said column jacket from the vehicle in response to movement of said column jacket along said longitudinal axis; 
 an energy absorption device coupled to said release module and defining a deformation channel and including a strap disposed within said deformation channel with said strap moveable through said deformation channel along a deformation path in response to movement of said column jacket along said longitudinal axis; 
 an axially extending pin moveable in an axial direction from a first axial position axially displaced outside of said deformation channel to a second axial position where said pin is disposed in said deformation channel such that said pin contacts said strap to alter said deformation path of said strap through said deformation channel for increasing a resistance force resisting movement of said strap through said deformation channel to increase an amount of energy absorbed; and
 an actuator for selectively moving said pin in the axial direction; 
 
 wherein said energy absorption device includes an anvil defining said deformation channel; and 
 wherein said anvil includes a first lobe and a second lobe and a depression disposed between said first lobe and said second lobe.